Some fuel delivery systems utilize an electric fuel pump disposed within a vehicle fuel tank to draw fuel from the fuel tank and deliver that fuel under pressure to the vehicles engine. Contaminants within the fuel tank, such as weld slag or other residual materials from the manufacturing of the fuel tank as well as contaminants added to the tank during its use, can damage the fuel pump if allowed to enter therein and severely effect the durability and reliability of the fuel pump. To prevent at least the most harmful contaminants from entering the fuel pump, fuel filters of various materials have been disposed adjacent to the fuel pump inlet to trap these contaminants. These fuel filters are generally relatively small in size and located directly adjacent and attached to the fuel pump inlet.
In use, fuel flows in one direction through the fuel filter and the contaminants trapped by the filter clog the pores of the filter material and thereby reduce the fuel flow through the filter. The reduced fuel flow through the filter and into the fuel pump can damage the fuel pump as its strains to draw sufficient fuel through its inlet to supply a sufficient amount of fuel to the vehicle engine. In extreme cases, the fuel filter can become so clogged that insufficient fuel is delivered to the engine severely affecting the performance of the engine.
In addition, increasingly strict governmental regulations are being imposed which limit the allowable escape to the atmosphere of hazardous hydrocarbon fuel vapors. In response to these regulations, many fuel delivery systems for internal combustion engines, such as for automobiles have incorporated fuel vapor management systems including fuel vapor collection canisters disposed some distance from the fuel tank and in communication with a vapor dome in the fuel tank through a vapor vent valve. In at least some of these fuel vapor management systems, a pressure drop created by the operating engine is used to purge fuel vapors from the carbon canister by drawing fuel vapor from the canister into an intake manifold of the engine for combustion within the engine. Thus, carbon canisters have been mounted away from the fuel tank and closer to the vehicle engine to facilitate purging of the fuel vapor from the carbon canister.